The research now in progress and that planned under this research grant is based on detailed light microscopic, ultrastructural and immunopathologic studies of the kidney in human and experimental renal diseases. Studies of Human Renal Disease will be done on renal biopsy, nephrectomy and autopsy specimens and to a considerable extent are dependent on the type and amount of material made available through the clinical services. Ongoing investigations are directed primarily to Renovascular Hypertension, Hyeloma Kidney, Lupus Nephritis and Renal Allografts. The morphologic findings are correlated with clinical and laboratory data. Experimentally three major projects are either in progress or will begin during the year: 1. Renal arteriolar changes induced by DCA-salt or renin-angiotensin hypertension with emphasis on the pre-hypertensive phase and on the "benign" to "malignant" transition phases; 2. Glomerular capillary lesions induced by enzymes and vasoactive amines, their evolution and repair; 3. Further studieswith the mouse model of Bence Jones nephrosis (cast nephropathy) developed in this laboratory during the past year by injecting light-chain protein (lambda type).